1. Activity – Simple Sweep

2. Preparation You will receive a hard foam block size about 150X150X150 File and sand your foam block to form a perfect cube  Faces are flat  Length of all sides equal  Faces perpendicular to each other On a cardboard, sketch and cut 2 curve templates slightly over 100 long. The more pronounce one will be your cross-section curve and the other your rail curve

3. Step 1 – Ruled Surface Cross-Section Curve

5. Switching From Sculpting to Sanding Beginners have a tendency to switch from sculpting to sanding too early The speed of material removal by sanding is dependent on the contact area and the press force (P=F/A) A rough but flat surface like A will take much shorter time to sand than smooth but bulging surface like B Although sanding is very accurate, it takes a long time to take down 1mm from a 150X150 surface! AB

6. Step 2 - Convex Sweep Surface Cross-Section Curve Rail Curve

9. Discussion Fine  Smooth  Fine Smooth

10. Step 3 - Saddle Sweep Surface Cross-Section Curve Rail Curve

11. Parting and Draft Drill 2 vertical holes through the foam block Use the remaining flat side as reference, saw the block into two-halves Join the halves together by round ABS studs Modify the side walls so that all draft angle >2° Keep your parting profile

12. Fine Tuning Modify the side walls so that all draft angle >2° Fine tune the surfaces until they are smooth ( 光顺 ) and fine ( 平滑 ) Keep your parting profile and edges sharp